1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
|
/****************************************************************************
**
** Copyright (C) 2015 The Qt Company Ltd.
** Contact: http://www.qt.io/licensing/
**
** This file is part of the QtXmlPatterns module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL21$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and The Qt Company. For licensing terms
** and conditions see http://www.qt.io/terms-conditions. For further
** information use the contact form at http://www.qt.io/contact-us.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 or version 3 as published by the Free
** Software Foundation and appearing in the file LICENSE.LGPLv21 and
** LICENSE.LGPLv3 included in the packaging of this file. Please review the
** following information to ensure the GNU Lesser General Public License
** requirements will be met: https://www.gnu.org/licenses/lgpl.html and
** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** As a special exception, The Qt Company gives you certain additional
** rights. These rights are described in The Qt Company LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** $QT_END_LICENSE$
**
****************************************************************************/
#include "qcommonsequencetypes_p.h"
#include "qemptysequence_p.h"
#include "qgenericsequencetype_p.h"
#include "qitemmappingiterator_p.h"
#include "qoptimizationpasses_p.h"
#include "qsequencemappingiterator_p.h"
#include "qforclause_p.h"
QT_BEGIN_NAMESPACE
using namespace QPatternist;
ForClause::ForClause(const VariableSlotID varSlot,
const Expression::Ptr &bindingSequence,
const Expression::Ptr &returnExpression,
const VariableSlotID positionSlot) : PairContainer(bindingSequence, returnExpression),
m_varSlot(varSlot),
m_positionSlot(positionSlot),
m_allowsMany(true)
{
Q_ASSERT(m_positionSlot > -2);
}
Item ForClause::mapToItem(const Item &item,
const DynamicContext::Ptr &context) const
{
context->setRangeVariable(m_varSlot, item);
return m_operand2->evaluateSingleton(context);
}
Item::Iterator::Ptr ForClause::mapToSequence(const Item &item,
const DynamicContext::Ptr &context) const
{
context->setRangeVariable(m_varSlot, item);
return m_operand2->evaluateSequence(context);
}
void ForClause::riggPositionalVariable(const DynamicContext::Ptr &context,
const Item::Iterator::Ptr &source) const
{
if(m_positionSlot > -1)
context->setPositionIterator(m_positionSlot, source);
}
Item::Iterator::Ptr ForClause::evaluateSequence(const DynamicContext::Ptr &context) const
{
const Item::Iterator::Ptr source(m_operand1->evaluateSequence(context));
riggPositionalVariable(context, source);
if(m_allowsMany)
{
return makeSequenceMappingIterator<Item>(ConstPtr(this),
source,
context);
}
else
{
return makeItemMappingIterator<Item>(ConstPtr(this),
source,
context);
}
}
Item ForClause::evaluateSingleton(const DynamicContext::Ptr &context) const
{
return evaluateSequence(context)->next();
}
void ForClause::evaluateToSequenceReceiver(const DynamicContext::Ptr &context) const
{
Item::Iterator::Ptr it;
const Item::Iterator::Ptr source(m_operand1->evaluateSequence(context));
riggPositionalVariable(context, source);
Item next(source->next());
while(next)
{
context->setRangeVariable(m_varSlot, next);
m_operand2->evaluateToSequenceReceiver(context);
next = source->next();
}
}
Expression::Ptr ForClause::typeCheck(const StaticContext::Ptr &context,
const SequenceType::Ptr &reqType)
{
const Expression::Ptr me(PairContainer::typeCheck(context, reqType));
const Cardinality card(m_operand1->staticType()->cardinality());
/* If our source is empty we will always evaluate to the empty sequence, so rewrite. */
if(card.isEmpty())
return EmptySequence::create(this, context);
else
return me;
/* This breaks because the variable references haven't rewritten themselves, so
* they dangle. When this is fixed, evaluateSingleton can be removed. */
/*
else if(card->allowsMany())
return me;
else
return m_operand2;
*/
}
Expression::Ptr ForClause::compress(const StaticContext::Ptr &context)
{
const Expression::Ptr me(PairContainer::compress(context));
if(me != this)
return me;
/* This is done after calling PairContainer::typeCheck(). The advantage of this is that
* m_allowsMany is updated according to what the operand says after it has compressed. However,
* if it was initialized to false(as it once was..), ForClause::evaluateSequence()
* would potentially have been called by PairContainer::compress(), and it would have
* used an unsafe branch. */
m_allowsMany = m_operand2->staticType()->cardinality().allowsMany();
return me;
}
SequenceType::Ptr ForClause::staticType() const
{
const SequenceType::Ptr returnType(m_operand2->staticType());
return makeGenericSequenceType(returnType->itemType(),
m_operand1->staticType()->cardinality()
* /* multiply operator */
returnType->cardinality());
}
SequenceType::List ForClause::expectedOperandTypes() const
{
SequenceType::List result;
result.append(CommonSequenceTypes::ZeroOrMoreItems);
result.append(CommonSequenceTypes::ZeroOrMoreItems);
return result;
}
ExpressionVisitorResult::Ptr ForClause::accept(const ExpressionVisitor::Ptr &visitor) const
{
return visitor->visit(this);
}
OptimizationPass::List ForClause::optimizationPasses() const
{
return OptimizationPasses::forPasses;
}
Expression::ID ForClause::id() const
{
return IDForClause;
}
QT_END_NAMESPACE
|
